FIG. 1 illustrates an aircraft powered by fuselage-mounted engines (not shown) which are each contained within a nacelle 3. It is necessary for technicians to gain access to the interior of each nacelle 3, and so cowl doors 6A and 6B are provided. These doors are shown in more detail in FIG. 2. The two doors 6A and 6B enclose the engine. To access the engines, the upper door 6A and lower door 6B swings open about pivot points 14A and 14B.
However, the doors 6A and 6B, in swinging open, causes edge 18 to invade the space within the nacelle 3, as indicated by dimension 24, which is the depth of the invasion. This invasion is undesirable where the clearance 27 (shown at a location remote from the invasion for clarity) between the engine 30 and the inner surface 33 of the nacelle is small: the invasion can cause the edge 18 to contact the engine 30, which is to be avoided.
Prevention of such contact by increasing the clearance 27 is, in general, not feasible, because the clearance 27 is determined largely by considerations of weight and aerodynamic drag of the nacelle 3, and these considerations take precedence over door geometry. Thus, to prevent contact between edge 18 and the engine 30, the door opening mechanism must be re-designed.